Mechanism for controlling position of discharge blocking flap for rotary mowing deck

ABSTRACT

A push and release operator control for selectively opening or closing the discharge blocking flap of a lawnmower. The first portion of travel of the actuator raises the discharge blocking flap toward its balance point. As the blocking flap reaches the balance point the actuator is released which allows the blocking flaps momentum to carry it through the balance point where gravity takes over to finish the travel. The actuator is reset by the blocking flaps motion after passing the balance point. Once the actuator is reset by the blocking flaps travel the same push and release of the actuator will return the blocking flap to it original starting position.

BACKGROUND OF THE INVENTION

The present invention relates to a method for controlling the flow of clippings from the discharge opening of a rotary mowing deck on powered lawn mowing equipment.

Previous attempts to control the discharge of clippings are based on selectively placing a movable flap in the discharge path of the clippings; the position of the flap is controlled by the mower operator and requires one motion to block the discharge and a separate motion to allow the discharge. The prior approach of Bellis Jr. as set forth in U.S. Pat. No. 6,874,309 shows a hand operated blocking flap located adjacent to the operator station. The flap can be operated without affecting the speed of the mower however the operator is required to free one hand to operate the flap this can be a problem on lever operated mowers. The problem of having a free hand to operate a flap is over come by Exmark Mfg Co, U.S. Pat. No. 7,594,379 B2, they use a foot pedal to operate the flap. The Exmark design utilizes an over center locking pedal to hold the flap in the closed position with separate release pedal to return the flap to the open position. The Exmark design allows the pedal to be partially depressed to feather the flow of clippings. There are disadvantages to the over center design. For example; the over center mechanism is complicated with many moving parts these can become clogged with debris from mowing causing the pedal to loose functionality; having an independent release forces the operator to recall which pedal to push to move the flap to the desired position. It would be desirable to have a single pedal that would open or close the blocking flap. In addition if the same pushing motion of the pedal could open or close the flap it would make it very simple to operate the flap.

DEFINITIONS

Throughout the application the following terms are used as defined below.

(a) Flap refers to the devise that physically covers the discharge opening to block clippings from exiting the mowing deck through the discharge opening.

(b) Pedal refers to the foot operated device used to engage and disengage the flap.

(c) TDC refers to top dead center which is the balance point when the flap will stand held only by gravity and the connecting pin friction assuming the mower is on essentially level ground.

(d) Forward direction is defined as the direction of travel the flap moves when the pedal is initially pushed.

SUMMARY OF THE INVENTION

The present invention is for a foot operated blocking flap for use on a rotary mower to control discharge of grass clippings and debris.

More specifically the invention allows control of the blocking flap with a single pedal. One aspect of the present invention is comprised of pivoting foot pedal, a linkage, a set of pivot joints and a pivoting flap. The configuration of the elements is such that when the pedal is fully depressed the flap is held in a balanced position between fully open and fully closed. Upon release of the pedal with the flap held still said flap and pedal will hold stationary. With the introduction of momentum the flap will tend to travel past the balance point on to the next stop raising the foot pedal as it goes. Once the flap is on the next stop the foot pedal can again be pushed to start the flap moving again only in the opposite direction.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts and wherein:

FIG. 1 is a perspective view depicting a partial mowing deck, the right frame member of the operator station, and the invention;

FIG. 2 is a side elevation view showing the flap and foot pedal with the flap in the closed position

FIG. 3 is a side elevation view showing the flap and foot pedal with the flap in the open position and

FIG. 4 is a side elevation view showing the flap and foot pedal with the flap in the TDC position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment. Referring to FIG. 1 the invention is composed of foot pedal 1, mounted to mower frame 2, flap 3 mounted to mowing deck 9 and linkage 4 connecting flap 3 to pedal 1. Pedal 1 is pivotally journalled to mount 7 by the pedal shaft 8, the axis of rotation for pedal shaft 8 is perpendicular to the main body of pedal 1. The mount 7 is attached to the mower frame 2 by clamping force or bolts, refer to FIG. 1 clamp assembly 5. The Journal 6 is attached to the inner mounting plate 7 at a 30 degree angle from level in the vertical plain. The linkage 4 is pivotally connected to foot pedal 1 at connecting joint 13, flap 3 is pivotally connected to linkage 4 at joint 12. Flap 3 is pivotally jounrnalled to mower deck 9 by rod 10. As force is applied to pedal 1 at point 11 it rotates about shaft 8 in direction A as indicated in FIG. 1. Referring to FIG. 4, Force is transferred to flap 3 via linkage 4 causing flap 3 to rotate until the connecting joint 12 aligns in plane E formed by flap axis of rotation 14 and the connection joint 13 of the pedal. At this configuration the center of gravity 15 of flap 3 will lie in plane F formed by the flap axis of rotation 14 and extending perpendicular to the plane of the mowing deck 9. On level ground flap 3 would balance and stand in the position of TDC.

Referring to FIGS. 2, 3, and 4, flap 3 is moved from blocking position B, FIG. 2, to open position B, FIG. 3, by applying and releasing pressure on pedal 1 at point 11. Starting in position B, FIG. 2, pressure is applied to pedal 1, flap 3 rotates in the clockwise direction toward TDC position D, FIG. 4, as flap 3 reaches TDC position D, FIG. 4, pedal 1 reaches rotation position G where pedal pressure is released to allow forward momentum to carry flap 3 through the TDC position D, FIG. 4, to open position B, FIG. 3, and pedal 1 from position G to position F.

To return flap 3 to blocking position B, FIG. 2, the same push and release motion is applied to pedal 1, point 11. Starting from position B, FIG. 3, pressure is applied to pedal 1, flap 3 rotates in the counter-clockwise direction toward TDC position D, FIG. 4, as flap 3 reaches TDC position D, FIG. 4, pedal 1 reaches rotation position G where pedal pressure is released to allow forward momentum to carry flap 3 through the TDC position D, FIG. 4, to closed position B, FIG. 2, and pedal 1 from position G to position E. 

1-13. (canceled)
 14. An apparatus for controlling the position of a pivotally mounted blocking plate located on the discharge opening of the cutting deck on a rotary lawn mower, comprising: a) a blocking plate mounted pivotally to said cutting deck at the discharge opening such that in the closed position the plate substantially prevents the discharge of clippings from the cutting deck and in the open position the plate substantially clears the discharge opening allowing the discharge of clippings from the cutting deck, b) a fixed pivot joint 1 with axis of rotation wherein said pivot joint 1 connects said blocking plate to the cutting deck, c) a blocking plate balance position along the rotational path of the blocking plate between the blocking plate closed position and the blocking plate open position where said blocking plate's motion, once stopped, will not begin again without an external force acting on the plate, d) a converting means for converting a motion supplied by a mower operator into a pulling force, e) a connecting means for transferring the pulling force to the blocking plate, Whereby said operator can control the position of the blocking plate using a like motion to alternately rotate the plate from the open position to the closed position and from the closed position to the open position.
 15. The apparatus of claim 14 wherein said converting means is a pedal comprising: a) a joint 3 linking the pedal to the connecting means, and b) a fixed pivot joint 4 pivotally connecting the pedal to the lawn mower, and c) a contact surface for receiving pressure from the mower operator, whereby the force to rotate the blocking plate in a forward and reverse direction can be supplied by the mower operator by applying pressure to the contact surface.
 16. The pedal of claim 15 wherein the pedal is foot operated, whereby the force to rotate the blocking plate in a forward and reverse direction can be supplied by the mower operator's foot by applying pressure to the contact surface thereby eliminating the need for the operator to reposition their foot or using two different motions to achieve the forward and reverse rotation of the blocking plate.
 17. The apparatus of claim 14 wherein the connecting means is comprised of: a) a linkage member with two ends, the first end being connected pivotally to said blocking plate and the second end to be locally exposed to a pulling force by mower operator, and b) a rotating pivot joint 2 connecting said linkage member to said blocking plate wherein the axis of rotation of pivot joint 2 is: i) substantially parallel to the axis of rotation of pivot joint 1, and ii) is positioned with respect to the blocking plate such that the axis of rotation of pivot joint 2 lies in the force plane formed by the intersection of the pulling force, force vector extending from the first end of the linkage member and the axis of rotation of pivot joint 1, when the blocking plate is positioned such that when the blocking plate is in motion said blocking plate's rotational momentum will power the plate past the balance position, whereby a variable pulling force applied axially at the second end of said linkage and controlled by the mower operator along with the blocking plate's momentum will rotate the blocking plate in a forward direction from the closed position past the balance position to an at rest open position, the pulling force being cyclical, said variable pulling force starting at zero when first applied to a maximum as the blocking plate approaches the balance position where the force is released allowing the blocking plate's momentum to carry the blocking plate past the balance position to the open position, once the blocking plate is in the open position said variable pulling force can again be applied to rotate the blocking plate in a reverse direction from the open position back toward the balance position where said blocking plate's rotational momentum will carry the plate past the balance position to an at rest closed position.
 18. The apparatus of claim 14, wherein the balance position is defined when the center of gravity of the blocking plate is positioned above the axis of rotation of pivot joint 1 and said center of gravity lies in the force plane formed by said axis of rotation of pivot joint 1 and gravity.
 19. A method for controlling the position of a pivotally mounted blocking plate located at the discharge opening of the cutting deck of a rotary lawn mower, comprising: a) providing a blocking plate mounted pivotally to the cutting deck at a fixed pivot joint 1 at the discharge opening such that in the closed position the plate substantially prevents the discharge of clippings from the cutting deck and in the open position the plate substantially clears the discharge opening allowing the discharge of clippings from the cutting deck, b) Providing a blocking plate balance position along the rotational path of the blocking plate between the blocking plate closed position and the blocking plate open position where said blocking plate's motion, once stopped, will not begin again without an external force acting on the plate, c) providing a linkage member with two ends, the first end being connected pivotally to said blocking plate at a rotating pivot joint 2 and the second end to be locally exposed to a pulling force by a mower operator, d) providing a pivot joint 2 connecting said linkage to the blocking plate and positioned such that the axis of rotation of pivot 2 is: i) substantially parallel to the axis of rotation of the pivot joint 1, and ii) is located with respect to the blocking plate such that the axis of rotation of pivot joint 2 lies in the force plane formed by the intersection of the pulling force, force vector extending from the first end of the linkage member and the axis of rotation of pivot joint 1, when the blocking plate is positioned such that when the blocking plate is in motion said blocking plate's rotational momentum will power the plate past the balance position, whereby a variable pulling force applied axially at said second end of said linkage and controlled by the mower operator along with the blocking plate's momentum will rotate the blocking plate in a forward direction from the closed position past the balance position to an at rest open position, said pulling force being cyclical, said pulling force starting at zero when first applied, reaches a maximum as the blocking plate approaches the balance position where the force is released allowing the blocking plate's momentum to carry said blocking plate past the balance position to the open position, once the blocking plate is in the open position said variable pulling force can again be applied to rotate the blocking plate in a reverse direction from the open position back toward the balance position where said blocking plate's rotational momentum will carry the plate to an at rest closed position.
 20. The method of claim 19, providing a balance position defined when the center of gravity of the blocking plate is positioned above the axis of rotation of pivot joint 1 and said center of gravity lies in the force plane form by said axis of rotation of pivot joint 1 and gravity.
 21. The method of claim 19 wherein the second end of said linkage is exposed to a pulling force supplied by mower operator with a foot pedal comprising: a) providing a pivotal connection between the pedal and the mower in the area of the operator station of the mower, b) providing a contact surface on the pedal for receiving pressure from the mower operator, said contact surface being located on one side of the pivot connection, c) providing a means for connecting the pedal to the second end of said linkage, whereby the force to rotate the blocking plate in a forward or reverse direction can be supplied by the mower operator's foot to apply said cyclical pressure to the pedal contact surface thereby eliminating the need for repositioning the operator's foot or using two different motions to achieve forward and reverse rotation of the blocking plate.
 22. An apparatus for controlling the position of a pivotally mounted blocking plate located on the discharge opening of the cutting deck on a rotary lawn mower comprising: a) a blocking plate mounted pivotally to said cutting deck at the discharge opening such that in the closed position the plate substantially prevents the discharge of clippings from the cutting deck and in the open position the plate substantially clears the discharge opening allowing the discharge of clippings from the cutting deck, said blocking plate having a balance position along the rotational path of the blocking plate between the blocking plate closed position and the blocking plate open position where said blocking plate's motion, once stopped, will not begin again without an external force acting on the plate, b) a fixed pivot joint 1 with axis of rotation wherein said pivot joint 1 connects said blocking plate to the cutting deck, c) a linkage member with two ends, the first end being connected pivotally to said blocking plate and the second end to be locally exposed to a pulling force by mower operator, d) a rotating pivot joint 2 connecting said linkage member to said blocking plate wherein the axis of rotation of pivot joint 2 is: i) substantially parallel to the axis of rotation of pivot joint 1, and ii) is located with respect to the blocking plate such that the axis of rotation of pivot joint 2 lies in the force plane formed by the intersection of the pulling force, force vector extending from the first end of the linkage member and the axis of rotation of pivot joint 1, when the blocking plate is positioned such that when the blocking plate is in motion said blocking plate's rotational momentum will power the plate past the balance position, whereby a variable pulling force applied axially at the second end of said linkage and controlled by the mower operator along with the blocking plate's momentum will rotate the blocking plate in a forward direction from the closed position past the balance position to an at rest open position, the pulling force being cyclical, said variable pulling force starting at zero when first applied to a maximum as the blocking plate approaches the balance position where the force is released allowing the blocking plate's momentum to carry the blocking plate past the balance position to the open position, once the blocking plate is in the open position said variable pulling force can again be applied to rotate the blocking plate in a reverse direction from the open position back toward the balance position where said blocking plate's rotational momentum will carry the plate to an at rest closed position.
 23. The apparatus of claim 22, wherein the balance position is defined when the center of gravity of the blocking plate is positioned above the axis of rotation of pivot joint 1 and said center of gravity lies in the force plane formed by said axis of rotation of pivot joint 1 and gravity.
 24. The apparatus of claim 22, wherein said second end of said linkage member has a foot pedal attached for supplying said pulling force comprised of: a) a joint 3 connecting the linkage member to the foot pedal, and b) a fixed pivot joint 4 pivotally connecting the foot pedal to the lawn mower, and c) a contact surface for receiving pressure from the mower operator's foot, said surface being located on one side of the pivot joint 4, whereby the force to rotate the blocking plate in a forward and reverse direction can be supplied by the mower operator's foot by applying said cyclical pressure to the contact surface thereby eliminating the need for the operator to reposition their foot or using two different motions to achieve the forward and reverse rotation of the blocking plate. 